Understanding the Microstructure and Properties of Components Fabricated by Laser Engineered Net Shaping (LENS)

Abstract

Laser Engineered Net Shaping (LENS) is a novel manufacturing process for fabricating metaI parts directly from Computer Aided Design (CAD) solid models. The process is similar to rapid prototyping technologies in its approach to fabricate a solid component by layer additive methods. However, the LENS technology is unique in that fully dense metal components with material properties that are similar to that of wrought materials can be fabricated. The LENS process has the potential to dramatically reduce the time and cost required realizing functional metal parts. In addition, the process can fabricate complex internal features not possible using existing manufacturing processes. The real promise of the technology is the potential to manipulate the material fabrication and properties through precision deposition of the material, which includes thermal behavior control, layered or graded deposition of multi-materials, and process parameter selection.

Compositionally graded metals: A new frontier of additive manufacturing

“…Some of the current technologies include direct metal laser sintering (DMLS), electronic beam melting, ultrasonic additive manufacturing (UAM), and laser engineered net shaping (LENSÒ also known as laser deposition). [5][6][7][8][9][10][11][12] In contrast to the ease in which AM can be applied to polymers, where low melting temperatures and relatively high viscosities allow for precise and continuous deposition, AM with metals presents a number of difficulties. The high melting temperatures of metals limit the available heating methods and the viscosity of molten metal is much lower than thermoplastic polymers so continuous feeding is difficult.…”

Influence of scanning speed on the microhardness property of additive manufactured titanium alloy

“…Also, LMD can be used to repair high valued component parts that are prohibitive to be repaired and discarded in the past (Ploude, 2003;Bergan, 2012) and can be used to make part with functionally graded materials (Liu and Dupont, 2003). Lots of research has appeared in the literature in the last decades on the influence of processing parameters on the evolving properties of Ti6Al4V alloy using LMD (Wu et al 2004;Griffith et al 2000;Srivastava et al 2001;Kelly and Kampe, 2004a;Brandl et al 2011;Kelly and Kampe, 2004b;Gharbi et al 2013;Schwender et al 2001;Mok et al 2008;Mahamood et al 2014b andKobryn et al 2000). However, a lot still needs to be fully understood about the underlying physics of the LMD process, the effect of scanning speed on the evolving microstructure and property of the laser metal deposited titanium alloy.…”

Modeling of Ti-W Solidification Microstructures Under Additive Manufacturing Conditions

“…LENS™ and other energy deposition-based AM processes have gathered interest because of their potential for producing parts with advantageous microstructural features, [1] unique structures, [2] and/or improved mechanical properties. [3] Additional abilities of such deposition processes include building of compositionally or functionally graded parts, [4] fully dense parts, and use in part repair. [5] Parts made from titanium alloys in particular, owing to its low density, high strength, and corrosion resistance, have the potential to be produced via LENS™ for applications ranging from biomedical to aerospace.…”